The EU will give Turkey $3 billion to to help stem the flow of refugees to Europe

European Union leaders signed an agreement with Turkey on Sunday, offering cash, visas and closer ties in exchange for Turkish help in stemming the flow of refugees to Europe.

Here are the key points of the deal.Turkey's President Tayyip Erdogan (R) meets with German Chancellor Angela Merkel at the Group of 20 (G20) leaders summit in the Mediterranean resort city of Antalya, Turkey, November 16, 2015. Reuters

Cash for refugees

The EU will provide "an initial" 3 billion euros ($3.2 billion) for Turkey to improve conditions for the 2.2 million or so Syria n refugees in the country. A key element is to provide Arabic-speaking schools and other services to encourage refugees not to head to Europe.

Turkey wanted 3 billion euros per year. The EU offered it over two years. The agreement does not specify, but ties the payments to Turkey's performance in reducing the numbers traveling. There are, however, no precise benchmarks on those numbers.

EU states have not agreed where the money will come from. The EU executive has suggested it put up 500 million euros from central funds and that the 28 member states pay the rest, according to their means.

States may also see their contributions exempted from EU fiscal rules if their overall spending on refugees is considered extraordinarily high by the European Commission.

But richer states, including Germany and France, want the whole amount paid centrally, even if that means eating into reserves in a budget that has been fixed until 2020. That would avoid potentially difficult parliamentary processes in some countries. Others, especially net recipients of EU aid in the east, are wary of draining the EU budget.Refugee braves rainstorm at the Greek-Macedonian border. Thomson Reuters

Accession chapters

EU foreign ministers will formally approve at their next meeting on Dec. 14 the opening of Chapter 17 of EU accession talks with Turkey.

In other words, negotiations will formally start on bringing Turkey's economic and financial policies and standards into line with the EU -- one of 35 chapters states must complete before being allowed to join the European Union.

Turkey also won a pledge, alongside the vague promise to "re-energize" the membership process formally launched a decade ago, that preparations would start to open other chapters. There is talk of, among others, Chapters 23 and 24, on judicial and rights issues.

But Cyprus, engaged in delicate negotiations to re-unite the island by securing a peace deal with Turkish-backed Northern Cyprus, has vetoed discussion on several chapters since a falling-out with Ankara over shipping treaties, and wants to hold Turkey to conditions before seeing accession talks progress further.

The European Commission has told Turkey that it could complete by the first quarter of next year the preparatory work for opening chapters 23 and 24, as well as 15 (energy), 26 (education) and 31 (foreign and defense policy).

Turkish Prime Minister Ahmet Davutoglu is welcomed by European Council President Donald Tusk at the start of an EU-Turkey summit in Brussels Thomson Reuters Many in the EU, and in Turkey, question whether Turkey ever will, or should, join the European bloc, whose membership now stands at 28 states.

The migration crisis could speed up the admission of a handful of small Balkan states which had been expected to be delayed well into the next decade. Turkey, with a fast-growing population of 78 million, would be the biggest state in the Union, yet much poorer than average.

As a Muslim country, it would be the only nation in the bloc not founded on Christian traditions. Few expect Turkey to join the EU within a generation, but a more active relationship is broadly welcomed on both sides.

Visa liberalization

The EU and Turkey already have an agreement dating from 2013 under which Turks should start being able to enter Europe's Schengen open travel zone without a visa once Ankara implements a pact to take back Turks and others who reach the EU from Turkey but fail to qualify for asylum.

Turkey is also supposed to tighten controls on Afghans, Pakistan is and other Asians coming across its borders, some them hoping to reach Europe. Sunday's accord pledges to accelerate new visa terms so that they can be active by October 2016 if Turkey meets set benchmarks.

Syrian refugees wait for transportation after crossing into Turkey from the Syrian town of Tal Abyad, near Akcakale in Sanliurfa province, Turkey, June 10, 2015. Osman Orsal/Reuters EU officials expect only a small number of the 78 million Turks to benefit at first from visa-free travel, most likely those given new-style, electronically readable passports. Groups to benefit would probably include business travelers and possibly students.

EU-Turkey summits

This is the first substantive point in Sunday's joint statement. Turkish President Tayyip Erdogan wants to intensify top-level dialogue with Europeans, who have increasingly shunned his company due to concerns about human rights in Turkey.

As with existing similar summits, such as with the United States or China, EU-Turkey summits are likely to involve only the heads of EU institutions in Brussels from the European side - Donald Tusk and Jean-Claude Juncker, the presidents respectively of the European Council and Commission.